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United States Patent | 6,082,679 |
Crouch ,   et al. | July 4, 2000 |
An active control method and apparatus for encouraging the early destruction of trailing vortices formed by a lifting body having at least two control surfaces on each side and creating multiple vortex pairs is provided. The method includes actuating the control surfaces in a manner leading to the direct excitation of one or more of the Transient Growth Mechanism, the Short Wavelength Instability, the Long Wavelength Instability, and the Crow Instability to result in the accelerated breakup of the trailing vortices. A method of selecting control parameters in an active control system includes identifying the near-field vorticity distribution of the aircraft, selecting at least one amplification mechanism for distorting the trailing vortices, determining amplitudes and wavelengths for imposed vortex perturbations, simulating trailing vortex evolutions, determining effectiveness of perturbations and amplification mechanisms, determining vortex positions as a function of control surface deflections, and determining control parameters to govern the movement of the wing control surfaces.
Inventors: | Crouch; Jeffrey D. (Issaquah, WA); Spalart; Philippe R. (Redmond, WA) |
Assignee: | The Boeing Company (Seattle, WA) |
Appl. No.: | 964941 |
Filed: | November 5, 1997 |
Current U.S. Class: | 244/199; 244/201; 244/203 |
Intern'l Class: | B64C 023/06; B64C 009/00; B64C 013/16 |
Field of Search: | 244/130,199,204,201,203 |
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